左耳钉的承诺右耳钉的誓言
[zuŏ ĕr dīng de chéng nuò yòu ĕr dīng de shì yán]
Wearing a stud on the left ear signifies a promise and one on the right a vow. The wearer uses earrings to silently articulate promises and solemn vows they wish others to understand beyond just their appearances.